Vexing Electrical Problem

[Dennis McDonaugh]

Sorry for the long story, but this has been going on a few days.

The circuit breaker for our second bedroom tripped a few days ago. It's used as an office and at the time the overhead light and ceiling fan were on as well as an LED TV and a cable box. I reset the breaker and it immediately tripped again so I turned the light and fan off and unplugged everything in the room, including those devices that weren't on at the time the breaker tripped. The breaker didn't immediately trip, but as soon as I turned on the overhead light it tripped. That was an "Aha" moment and I thought I'd discovered the issue. Just to make sure I turned the light off, reset the breaker and turned the light on and...nothing. Then, I turned on the ceiling fan and it tripped the breaker again. At that point I pulled the ceiling fan and light fixture down, checked the wiring and reinstalled them. I turned everything on and the breaker didn't trip...until a couple hours later.

This time I disconnected the black leads from the two switches that control the ceiling fan and light. Then I reset the breaker and it didn't trip so I just figured I had some kind of internal wiring problem in the fan or switches and decided to pick up a fan and two light switches from the big box store on the way home from work the next day. I reconnected the switches, plugged everything back in and told Kathy not to turn the overhead light or fan on. About noon I got a call from Kathy and she says the entry foyer light is "burned out" and we don't have any extra bulbs, can I pick up one from the store when I get the fan. I tell her sure and think nothing more of it. A couple hours later she calls and tells me the hall light is also out and the circuit breaker in the second bedroom tripped again because nothing electrical in the room works. I decided to skip buying the fan and investigate some more.

The circuit labeled Bedroom 2 in the breaker box powers the outlets in the bedroom, the overhead fan and light in the bedroom as well as the hall light, the light in the foyer and a light over the breakfast area in the kitchen. All lights except the kitchen light use low wattage CFLs. The kitchen uses a 60 watt incandescent bulb.

Armed with this knowledge I disconnected the overhead light and fan switches in the bedroom again. That left the switchs, light and fan unpowered. Then I turned on the hall, foyer and kitchen lights and they ran all night and half the next day until the breaker tripped. I had Kathy reset the breaker and turn off the kitchen and foyer light. The hall light ran for a couple days and then tripped the breaker. I turned off the hall light and turned on the foyer light and its still running.

At this point I'm thinking the breaker may be the issue. One other piece of information--the breaker is a GFI breaker, but as near as I can tell, none of the outlets it powers are outside or in a wet area. I checked the outlets in the laundry and bathroom and this breaker definitely doesn't power any of them or the outlets near the front and back door.

[Andrew Pitonyak]

I suppose that the problem could be up stream or down stream of the fan. When I had a similar problem, it turned out that one of the feeder plugs downstream had come loose. Can't tell you how much time I spent looking at the suspect plugs and hard-wired light before I found the loose wire that had been sparking in the wall.

I expected you to say that you had an Arc-Fault breaker feeding the bedroom, not a Ground Fault breaker.

[Wade Lippman]

GFCI problems can be devilishly hard to find.
So the obvious question... why is it a GFCI outlet? You really shouldn't have lights and fans on one.

[Dennis McDonaugh]

I suppose that the problem could be up stream or down stream of the fan. When I had a similar problem, it turned out that one of the feeder plugs downstream had come loose. Can't tell you how much time I spent looking at the suspect plugs and hard-wired light before I found the loose wire that had been sparking in the wall.

I expected you to say that you had an Arc-Fault breaker feeding the bedroom, not a Ground Fault breaker.

I hadn't thought about checking the plugs, but I'll do that too.

[Dennis McDonaugh]

GFCI problems can be devilishly hard to find.
So the obvious question... why is it a GFCI outlet? You really shouldn't have lights and fans on one.

That is puzzling since a GFCI breaker cost so much more than a standard breaker. My first inclination would be to replace it.

[Dennis McDonaugh]

While thinking on this at my desk I realize that there is a GFCI outlet next to the AC unit which is right outside the bedroom. I would have thought that it would be on the same circuit as the outlet near the front and rear doors, but maybe it comes from the bedroom circuit. I'll have to check that out when I get home.

[Mark Bolton]

You said the room is/was a bedroom. Not sure of the age of the home but it may be an AFCI not GFCI as they are required in sleeping rooms.

You may try picking up a new breaker and swapping out your old one as it may well be the breaker itself. The price hurts but its worth a try. I have had several occasions, especially on large circuits (hot tubs mainly) where the GFCI breakers seem to get weak/fussy over time and simply will not stop tripping. Ive spoken with squareD reps about it and there is never a reasonable answer. Swap out the breaker, and the problem is fixed (because there is no fault).

[Mark Bolton]

While thinking on this at my desk I realize that there is a GFCI outlet next to the AC unit which is right outside the bedroom. I would have thought that it would be on the same circuit as the outlet near the front and rear doors, but maybe it comes from the bedroom circuit. I'll have to check that out when I get home.

There shouldnt be a GFCI outlet behind a GFCI breaker. My guess would be the outdoor outlets are on a separate circuit but who knows.

[Dennis McDonaugh]

You said the room is/was a bedroom. Not sure of the age of the home but it may be an AFCI not GFCI as they are required in sleeping rooms.

You may try picking up a new breaker and swapping out your old one as it may well be the breaker itself. The price hurts but its worth a try. I have had several occasions, especially on large circuits (hot tubs mainly) where the GFCI breakers seem to get weak/fussy over time and simply will not stop tripping. Ive spoken with squareD reps about it and there is never a reasonable answer. Swap out the breaker, and the problem is fixed (because there is no fault).

It's a little over a year old Mark. I just noticed it had a test button on the breaker and figured it was a GFCI type. I'm going to check the wiring on all the outlets too. I'll replace the breaker once I've checked the wiring on all the lights and outlets. I'm halfway there already.

[Brian Elfert]

It's a little over a year old Mark. I just noticed it had a test button on the breaker and figured it was a GFCI type. I'm going to check the wiring on all the outlets too. I'll replace the breaker once I've checked the wiring on all the lights and outlets. I'm halfway there already.

It may very well be an Arc Fault breaker then. Some electricians hate them because of false trips and the callbacks that they generate.

[Mike Wilkins]

A defective power strip in that circuit could cause this to happen. I had one of the wall circuits in my shop that kept tripping. It was not until I unplugged the power strip did I find the problem. No power strip, no circuit breaker tripping. Worth a look.

[Kevin Bourque]

I'll bet that if you changed the GFI breaker to a standard breaker your mystery would be solved.
Most GFI breakers are set up to supply a few bathroom outlets. Not lights or ceiling fans.

[Dennis McDonaugh]

A defective power strip in that circuit could cause this to happen. I had one of the wall circuits in my shop that kept tripping. It was not until I unplugged the power strip did I find the problem. No power strip, no circuit breaker tripping. Worth a look.

I don't think there is a power strip on that circuit, but I'll double check other outlets that are physically close to the room just to make sure.

[Mark Bolton]

It's a little over a year old Mark. I just noticed it had a test button on the breaker and figured it was a GFCI type. I'm going to check the wiring on all the outlets too. I'll replace the breaker once I've checked the wiring on all the lights and outlets. I'm halfway there already.

If its a year old it more than likely an AFCI. The requirement for AFCIs in sleeping rooms and in some areas nearly every room in the house started several years ago.

P.S. I wouldnt go crazy tearing things apart until you try swapping the breaker. As Brian eluded, these breakers (as any fault breaker) are known to be a real pain in the backside. I know many would simply swap the breaker out for a non-fault breaker, but I'd try a new AFCI and I'll bet your problem will go away.

[Erik Loza]

My money is on "AFCI". We had a similar issue and that was the cause. New construction, in our case.

Erik Loza
Minimax USA

[Tom M King]

My money is on the breaker too.

[Von Bickley]

My money is on "AFCI". We had a similar issue and that was the cause. New construction, in our case.

Erik Loza
Minimax USA

I agree with Erik.

If it was my house, I would replace the breaker with a regular breaker and check it out that way. I am a retired electrician and I do not have any of the arc breakers in my house. I replaced all the arc breakers with regular breakers after the inspection. The inspector suggested I do that.

[Dennis McDonaugh]

dadgummit

I bought another AFCI breaker and installed it this evening. Everything looked good until I reconnected the ceiling fan and light switches in the bedroom, then the breaker tripped. I disconnected both switches and no tripping. I reconnected the light switch and left the fan switch disconnected and every time I flipped the switch on or off the breaker tripped. Then I disconnected the light switch and reconnected the fan switch and it did not trip the breaker when I flipped it between on and off. I guess my question is it possible that the switch is arcing inside when it is turned from on to off? If it is the switch, why did the breaker trip after several hours with that switch disconnected? I'm going to pick up a couple good quality switches tomorrow and a few regular 20 amp breakers.

[Phil Thien]

dadgummit

I bought another AFCI breaker and installed it this evening. Everything looked good until I reconnected the ceiling fan and light switches in the bedroom, then the breaker tripped. I disconnected both switches and no tripping. I reconnected the light switch and left the fan switch disconnected and every time I flipped the switch on or off the breaker tripped. Then I disconnected the light switch and reconnected the fan switch and it did not trip the breaker when I flipped it between on and off. I guess my question is it possible that the switch is arcing inside when it is turned from on to off? If it is the switch, why did the breaker trip after several hours with that switch disconnected? I'm going to pick up a couple good quality switches tomorrow and a few regular 20 amp breakers.

Well you're leaking somewhere, in the fan or something plugged into a receptacle.

An electrician would disconnect at the breaker and use a megger to check for leakage from white to ground. The megger is like a ohmmeter on steroids and will find resistances as high as a million ohms. You can try using a high-quality VOM but it likely can't find the very minute leakage occurring. But you can try. Measure white to ground to start. Look for any continuity whatsoever.

[Von Bickley]

Dennis,
I would disconnect the wires going to the arc breaker and temporally connect that circuit to another regular breaker that is in your panel. Lights and fans are going to arc when you put power to them, so much for the arc breaker.
If the circuit works on a regular breaker, I would replace the arc breaker with a regular breaker. This test will not cost you anything and you can connect the wires to an existing breaker just to see if it will work O.K.

[Scott T Smith]

I have a different perspective than some of the other posters. If an AFCI breaker is tripping, and you've replaced the breaker and the new one still trips, you have a problem in the circuit that needs to be addressed.

Replacing the AFCI with a standard breaker will not solve the root cause of the problem, but it could allow an electrical fire to occur that would be prevented by the AFCI.

Six years ago I lost my woodshop due to fire - most likely caused by an electrical short. Standard breakers do not trip due to arc faults, and both the Fire Inspector and myself believe that an arc fault was the root cause of the fire.

I would strongly discourage you from replacing the AFCI with a regular breaker. Instead, trace down the cause of the tripping and address it.

[Jim Matthews]

I thought the AFCI was designed to prevent sputtering and overheating as fire sources.

If the local code calls for this, there may be a history of fires in your area
that were traced to electrical faults that the AFCI helps prevent.

Is this a Seasonal problem? The sensor may be oversensitive, as suggested.
There's even a page for this on the AFCI information site.

http://www.afcisafety.org/report.html

[Dennis McDonaugh]

Thanks for the input guys. Like Scott, the fact that the new breaker also trips leads me to believe I have an issue that needs addressed. Here's where I'm at this morning. With the switch to the light disconnected, The breaker didn't trip over night which is an improvement over what I had before. Right now, it only trips when the light switch is in the circuit and you turn the light on or off, so either the switch, the wire from the switch to the ceiling fan or the ceiling fan or light is to blame. I have taken the ceiling fan down and made sure the connection to the house wiring was secure. Today, I'm going to replace the light switch to start with, then move to the light and finally the fan if the problem persists. That still doesn't explain why the breaker would trip for no apparent reason, but maybe I had a bad switch and a wonky breaker.

[Pat Barry]

This is an interesting problem. I agreee with many of the responses and agree that at this point you need to believe there is something wrong. I don't think its something wrong with the AFCI breaker since you have changed it. I am thinking that the problem could be much more subtle and hard to find. For example, there could be a nail, inadvertently placed for something as a picture that was recently or long ago hung on the wall that punctured the wire outer jacket or insulation behind the wall and now has begun to cause problems. Finding this could be a nightmare. SO the simplest thing is to look at what has changed recently that mmight have caused the problem to occur. Did you put a nail in the wall to hang a picture? Anything like that should be investigated as a possible cause.

Anyway, here is a link to a site I found that mmight give you some other ideas

http://www.thecircuitdetective.com/afci_circuit_breakers.htm

In this article they mention that some of these breakers have an indicator of whether the fault was an arc fault or a ground fault.. Just my 2 cents but I suspect yours is more likely a ground fault than an arc fault given the description you have supplied. That is why I suggested the idea of a nail puncturing the insulation on the wire.

[ray hampton]

what type of lights do you have ? , the lights may be your problem

[Val Kosmider]

I agree with Erik.

If it was my house, I would replace the breaker with a regular breaker and check it out that way. I am a retired electrician and I do not have any of the arc breakers in my house. I replaced all the arc breakers with regular breakers after the inspection. The inspector suggested I do that.


New construction. The GFCI was somehow affected by one of the overhead florescent lights in the basement. Sometimes it worked, other times it would 'blow' ten times in ten minutes. I did the naughty and replaced everything (temporarily, of course) with standard stuff. Problem solved.

Just some weird electronic gremlin that the GCFI outlets didn't like the 'field' generated by the fluorescents.

[Tom M King]

Once you have it so it stays on for a while like it is, flip the switches on any other circuit that might have been used during the time where it was later found to have tripped the breaker. If you can find such a circuit that does trip the breaker, search for shared neutrals with the offending circuit. In that case, easiest fix would be to nut the neutral on one of those circuits, and pull a separate neutral, so there are no shared neutrals. We just traced down such a problem today.

[Dennis McDonaugh]

Pat. I'm going to rewire all the outlets, switches and lights today. I can't really do anything about the wire inside the wall at this point.

Thanks for the link.

[Dennis McDonaugh]

Ray, they are regular light fixtures and all but one has a CGL light bulb, the other has a incandescent. The one with an incandescent light is an antique and has a two wire light fixture retrofitted, I added a ground to the metal fixture years ago. It has been operating with no issues for almost a year, but its the first light fixture I would suspect of causing the problem if the light switch in the bedroom didn't immediately trip the breaker.

[Dennis McDonaugh]

I'm not following you Tom, aren't all neutrals shared?

[Dennis McDonaugh]

I didn't get to work on it yesterday, but with both light and fan switches disconnected in the bedroom the circuit doesn't immediately trip, but will after a period of time whether you use any other device or light in the house. Sometime it trips fairly quickly and other times not for hours. Nothing is plugged into any of the outlets on the circuit.

Today I am replacing both switches in the bedroom and rewiring all the outlets and light fixtures. After that I'm at a loss.

[Dennis McDonaugh]

I disconnected the antique light fixture in the kitchen and the light in the hall. The hall light is on a 3-way switch if that makes a difference. The breaker hasn't tripped so far.

None of the outlets have anything plugged into them much less anything powered
The bedroom fan and light switches are disconnected
The hall and kitchen light fixtures are removed

These items are powered
outlets
two hall light switches
foyer light and switch
kitchen light switch

I figure process of elimination is my best bet now.

[Pat Barry]

I figure process of elimination is my best bet now.
Yes - I agree - good luck

[Mike Lassiter]

I have a different perspective than some of the other posters. If an AFCI breaker is tripping, and you've replaced the breaker and the new one still trips, you have a problem in the circuit that needs to be addressed.

Replacing the AFCI with a standard breaker will not solve the root cause of the problem, but it could allow an electrical fire to occur that would be prevented by the AFCI.

Six years ago I lost my woodshop due to fire - most likely caused by an electrical short. Standard breakers do not trip due to arc faults, and both the Fire Inspector and myself believe that an arc fault was the root cause of the fire.

I would strongly discourage you from replacing the AFCI with a regular breaker. Instead, trace down the cause of the tripping and address it.

Some time back our refrigerator started acting up. Open the door and the inside light sometimes would be very dim, other times it was bright but would be erratic in light output. I thought the bulb was "going bad", but didn't really think too much about it. The refrigerator is the last receptacle on the counter receptacles in the circuit. I cannot exactly recall now why I did this or what caused me to; but beside the refrigerator sits a Kitchen Aid mixer that basically stays plugged in all the time. I removed the power plug from the receptacle to find the molded plug was discolored from white to a brownish color. But the real shocker was the receptacle itself was black and melted. The plug on the mixer had prevented this from being seem.

When I removed the face plate and the receptacle I found wires had become loose at the screws holding them ( lived here about 14 years at the time ) and with the current draw from the refrigerator being supplied by the wires on this receptacle it was causing heat to build up. It had already got the wire hot enough that the insulation had melted about an inch or so from the naked wire. This was just before burning our house down. With the mixer plugged into the wall receptacle you couldn't see the heat caused damage. I think I noticed the mixer plug being discolored was the reason for investigating further and finding this.

With that said I have to agree with Scott! DONOT take this lightly. Something is not right, and while changing the breaker out for a non Arc Fault style may stop the breaker from tripping it may also cause your house to burn up. I don't want to hear about that happening! I think you are on the right track investigating this to the best of your ability and if you come up empty handed I suggest you call in someone.

Good luck.

292038292039292040292041

[Dennis McDonaugh]

I agree with you Mike. Right now I'm just trying to disconnect something that will make it stop blowing the breaker! So far so good today.

[Dennis McDonaugh]

I picked up a couple 20 amp switches--overkill I know, but right now I'm more interested in stopping the issue than saving money. I'll replace them tomorrow, hopefully after the breaker doesn't trip today.

[ray hampton]

Ray, they are regular light fixtures and all but one has a CGL light bulb, the other has a incandescent. The one with an incandescent light is an antique and has a two wire light fixture retrofitted, I added a ground to the metal fixture years ago. It has been operating with no issues for almost a year, but its the first light fixture I would suspect of causing the problem if the light switch in the bedroom didn't immediately trip the breaker.

I doubt that the switch are bad more likely a wire going to /from the switch are going to ground, the wire could be at a light or other device

[Dennis McDonaugh]

[/COLOR]
I doubt that the switch are bad more likely a wire going to /from the switch are going to ground, the wire could be at a light or other device

By disconnecting the light at the switch I can eliminate the wire from the switch to the light. I can't do much about the wire from the breaker to the first switch or outlet.

[Dennis McDonaugh]

tripped again dang it

[Dennis McDonaugh]

Looking at the link Pat provided, I see my symptom is listed in category C, AFCI trips between 1 minute and 1 month. There are 3 causes given, overload, bad breaker and arc fault. Obviously the circuit is not overloaded, it trips with nothing connected to it. I don't think the breaker is bad since I replaced it and got the same symptom with the second one. That leaves an arc fault which is hard to find. I can make sure all the outlets, lights and switches have good connections, but can't access anything in the walls.

[Chris Padilla]

Interesting albeit frustrating problem. I would think a bit and search a bit on what exactly is entailed and involved with an "arc fault" on the breaker. It might help you track down the culprit if you understand the common causes of an arc fault. Loose connections are an obvious one but assuming you've taken care of that, what else causes them?

[ray hampton]

Dennis , this will sound crazy BUT do you have bugs or animals in the wall that may be in contact with the wires

[Mike Lassiter]

Looking at the link Pat provided, I see my symptom is listed in category C, AFCI trips between 1 minute and 1 month. There are 3 causes given, overload, bad breaker and arc fault. Obviously the circuit is not overloaded, it trips with nothing connected to it. I don't think the breaker is bad since I replaced it and got the same symptom with the second one. That leaves an arc fault which is hard to find. I can make sure all the outlets, lights and switches have good connections, but can't access anything in the walls.

I maybe wrong BUT (that never stopped me:eek:) I am thinking arc fault too. I don't see how you could have a arc within a circuit if nothing is drawing current of some degree. Just having a loose connection in the circuit shouldn't arc with no load as there isn't a complete circuit to anything. I suggest you have something else in this circuit still that you haven't identified yet being apart of it. The only other thing comes to mind would be perhaps water has gotten into something, but not sure how or if that could do it.

You mentioned about disconnecting a light switch to kill power to a light. This brings a question to mind. Is the power for the light from the box the light switch is located in, and the wire from the switch is sending power to the light, or is it a "switch leg" that is getting power in the box the light itself is in, and being feed power from the light to the switch and back to the light to complete the circuit? Assuming you are turning off breaker to disconnect wires on the switch, then turning breaker back on - if power is coming from the light to the switch you have one of the two wires between the light and switch hot regardless of the switch being on or off that could be the problem area.

[Mike Lassiter]

I disconnected the antique light fixture in the kitchen and the light in the hall. The hall light is on a 3-way switch if that makes a difference. The breaker hasn't tripped so far.

None of the outlets have anything plugged into them much less anything powered
The bedroom fan and light switches are disconnected
The hall and kitchen light fixtures are removed

These items are powered
outlets
two hall light switches
foyer light and switch
kitchen light switch

I figure process of elimination is my best bet now.

It could depending on which way it is flipped. You have to have 3 wires for 3 way switches to work. As I was taught one is a "traveler" that connects the two switches together so regardless of which switch is used power will still get to the load. So if you regularly use the same switch one wire is sort of out of the loop until the other switch is flipped and them it would come into play. Don't know if my remarks are explaining what I am trying to say exactly, but with a single switch that switch will always be the point the power is switched on or off. If you have 3 way switches you have to replace a simple on/off with another 3 way and have two of them for the circuit to work. Power will go from one switch to the other thru the extra wire which could be a problem if something is loose. Not sure it would/could if you had the light removed as again no load, nothing to arc with a open circuit unless a short type connection.

[Dennis McDonaugh]

disconnected the foyer light at the ceiling, no trips for 3 hours

[Dennis McDonaugh]

I maybe wrong BUT (that never stopped me:eek:) I am thinking arc fault too. I don't see how you could have a arc within a circuit if nothing is drawing current of some degree. Just having a loose connection in the circuit shouldn't arc with no load as there isn't a complete circuit to anything. I suggest you have something else in this circuit still that you haven't identified yet being apart of it. The only other thing comes to mind would be perhaps water has gotten into something, but not sure how or if that could do it.

You mentioned about disconnecting a light switch to kill power to a light. This brings a question to mind. Is the power for the light from the box the light switch is located in, and the wire from the switch is sending power to the light, or is it a "switch leg" that is getting power in the box the light itself is in, and being feed power from the light to the switch and back to the light to complete the circuit? Assuming you are turning off breaker to disconnect wires on the switch, then turning breaker back on - if power is coming from the light to the switch you have one of the two wires between the light and switch hot regardless of the switch being on or off that could be the problem area.

Good question, I think the light is powered from the switch because there are only three wires in the ceiling box.

[Dennis McDonaugh]

It could depending on which way it is flipped. You have to have 3 wires for 3 way switches to work. As I was taught one is a "traveler" that connects the two switches together so regardless of which switch is used power will still get to the load. So if you regularly use the same switch one wire is sort of out of the loop until the other switch is flipped and them it would come into play. Don't know if my remarks are explaining what I am trying to say exactly, but with a single switch that switch will always be the point the power is switched on or off. If you have 3 way switches you have to replace a simple on/off with another 3 way and have two of them for the circuit to work. Power will go from one switch to the other thru the extra wire which could be a problem if something is loose. Not sure it would/could if you had the light removed as again no load, nothing to arc with a open circuit unless a short type connection.

At one point yesterday, flipping either switch for the hall light caused the circuit breaker to trip, but now it doesn't have an impact. The light is sitting on the hall table though.

[Dennis McDonaugh]

Tripped again.....:mad::mad: This time I couldn't reset it until I disconnected the switch for the kitchen light.

So both hall switches are disconnected from the power
The hall light is disconnected at the ceiling
The bedroom fan and light are disconnected at the switch box
The foyer light is disconnected at the ceiling
The kitchen light is disconnected at the switch and the ceiling
There are five outlets powered by the circuit all are connected, but have no load.
There's not much left to disconnect
It looks like the wiring goes to the hall light switch and hall light first, then the bedroom light and fan switch and from there down to the outlets. I don't know what box supplies power to the foyer, but I bet it goes to there before going to the kitchen light switch. I have so many wires loose I can start doing some continuity checks to find out where the short is,

[Duane Meadows]

Just a thought, are you near any radio, tv, ham, or cb transmitters? The longer the wiring run, the more of a chance of picking up a stray signal... the wiring can make pretty effective antennas. Light dimmers on other circuits, GDO transmitters, satelite recievers with poor connections. Possibilities get nearly endless.

[Von Bickley]

Looks like you have tried everything except a regular breaker.......

[Dennis McDonaugh]

No, not very close.

[Dennis McDonaugh]

Looks like you have tried everything except a regular breaker.......

I have been trying to avoid that since it appears that I do have a problem Von.

[Dennis McDonaugh]

Finally some concrete data. I measured the resistance between the ground wire and black wire going to the light box in the kitchen and it has a little over 1 meg ohm of resistance. I'm not sure why that has given me the symptoms I've got when that switch is turned off though.

[Scott T Smith]

Interesting albeit frustrating problem. I would think a bit and search a bit on what exactly is entailed and involved with an "arc fault" on the breaker. It might help you track down the culprit if you understand the common causes of an arc fault. Loose connections are an obvious one but assuming you've taken care of that, what else causes them?

A staple driven too deep into romex can cause an arc fault. What happens is that over time (and wire heating up) the insulation can thin out a bit, and the current will start an arc between the staple and the wire. It will not trip a standard breaker. As the arc increases it can cause the staple to become red hot, thus starting a fire.

[Tom M King]

I'm not following you Tom, aren't all neutrals shared?


A lot of older houses were wired with separate circuits sharing a neutral somewhere in the circuit-not in the panel. It saved a few bucks, but won't work with single pole AFCI breakers. The house we had the problem with had more junction boxes in it than any other six combined that I had ever seen. They had two hots in several, and even three in one. I have no idea how it ever passed inspection. It was built in the '60s, and had been "rewired" a couple of times since.

It had some conductors still from the old wire with no ground wire. Fortunately, all the old two conductor wires didn't have any staples in the wall, but only used the built in clamp in the metal boxes, so we were able to pull it straight down, pulling in new wires. Only one wall receptacle in the whole house had wires running horizontally in the wall, and we were able to access that one through the back of a vanity in the bathroom on the other side of that wall.

Do a google search for AFCI shared neutral problems, and you should find some info if you think there is any possibility that it might be a problem in your house. Sometimes it's easiest just to pull a new wire. The little fiberglass rods help to hit a box hole from above or below, when it's too hard with a fish tape.

[Tom M King]

I use this: http://www.homedepot.com/p/Klein-Tools-15-ft-Splinter-Guard-Glow-Rod-Set-56415/204178243?N=5yc1vZbm6i

read the reviews

If you have a fairly open stud cavity-top to bottom- sometimes it's easiest to drop a mason's line in with a weight, and snap it through the bottom hole with a bent wire hook, than to use a fish rod or tape.

[Dennis McDonaugh]

I'm just confused. With everything connected, I have some resistance between the hot and ground (not neutral) on all the outlets and most of the light switches. All the switches are tied to the main via pigtail, but the outlets are connected directly with the input and output wires connected directly to the outlet.

Once I identified the problem I started looking for the first switch box or outlet in the circuit. I disconnected the pigtail in the bedroom, there were three wires coming into the box, two from the top and one from the bottom. I assumed the main was one coming in the top as the other wire goes to the fan itself. There is an outlet below the switch and I assumed the wire that goes down went to that outlet and from there to the rest of the outlets in the room.

Here's the thing, the wire coming from below and one coming from the top (not the one that goes to the fan) both have some resistance between ground and hot. The wire going to the fan does not, but then its not connected to anything except the fan. That would indicate that there is a problem on both legs, but that seems highly unlikely.

Once I disconnected the pigtail in the bedroom switch box, I measured infinite resistance between the hot and ground in the other switch boxes.

I thought switch boxes and outlets were wired in series, but that isn't what I'm seeing unless I'm not thinking about this right. What am I missing?

[Dennis McDonaugh]

More progress.

there is an outlet in the hallway, I disconnected the it from the circuit and the problem went away in the hallway switch. They were close enough that I could ohm out the wire and that outlet feeds the switch. Once I reconnected the outlet the problem returned to the switch.

Power goes from the hall outlet to the hall switch and light, then to the foyer switch and light and on to the kitchen.

I just need to figure out the bedroom electrical arrangement.

[Dennis McDonaugh]

More information.

I reconnected everything except the pigtail in the bedroom switch box and turned the circuit breaker back on. I have 120 VAC on one wire in the box and nothing on the other two which confirms that box is the first box in the circuit.

[ray hampton]

I'm just confused. With everything connected, I have some resistance between the hot and ground (not neutral) on all the outlets and most of the light switches. All the switches are tied to the main via pigtail, but the outlets are connected directly with the input and output wires connected directly to the outlet.

Once I identified the problem I started looking for the first switch box or outlet in the circuit. I disconnected the pigtail in the bedroom, there were three wires coming into the box, two from the top and one from the bottom. I assumed the main was one coming in the top as the other wire goes to the fan itself. There is an outlet below the switch and I assumed the wire that goes down went to that outlet and from there to the rest of the outlets in the room.

Here's the thing, the wire coming from below and one coming from the top (not the one that goes to the fan) both have some resistance between ground and hot. The wire going to the fan does not, but then its not connected to anything except the fan. That would indicate that there is a problem on both legs, but that seems highly unlikely.

Once I disconnected the pigtail in the bedroom switch box, I measured infinite resistance between the hot and ground in the other switch boxes.

I thought switch boxes and outlets were wired in series, but that isn't what I'm seeing unless I'm not thinking about this right. What am I missing?

the switch and the outlets are wire in series WHICH MEAN that the current will not flow to the outlet if the switch is turn off unless there is a defect in the wiring

[ray hampton]

Finally some concrete data. I measured the resistance between the ground wire and black wire going to the light box in the kitchen and it has a little over 1 meg ohm of resistance. I'm not sure why that has given me the symptoms I've got when that switch is turned off though.


if your meter shows a reading between the hot black wire and the green ground wire THEN THEY must be touching at some point alone their path

[Mike Lassiter]

More information.

I reconnected everything except the pigtail in the bedroom switch box and turned the circuit breaker back on. I have 120 VAC on one wire in the box and nothing on the other two which confirms that box is the first box in the circuit.

Dennis I have been working on this with you (LOL) as I have been doing other things today. I am curious if you disconnected the power wire from the breaker and rechecked the circuit with the ohm meter if you would still get a ohm reading. Why I am thinking this is the breaker has a pigtail wire on it that goes to the buss bar on the neutral (or ground not sure on arc fault) which would electrically somehow tie them together inside the breaker I would think. I wonder if you are getting a reading from that and not a wiring issue. By disconnecting the power wire from the breaker you would eliminate the breaker from being a potentially high ohm electric conductor. If my thinking is right the breaker itself could be the source of the mega ohm reading you are seeing across the hot and ground wires. It likely shouldn't be a issue and has to do with how the arc fault is able to detect or operate.
I have worked on complicated wiring problems on computer controlled Allison transmissions and got weird ohm readings because of getting some continuity thru the circuit board in the ECU module when the harnesses were still connected to it. Regardless of anything being connected in the branch circuit you are working on, if the breaker is electrically connected to the power and ground internally it could give you a very high ohm reading. Even flipping the breaker off wouldn't prevent that I would assume as the electrical circuit would be on the load side of the breaker internally when flipping it off that connection I would think would still be there - just without power now.

You replaced the arc fault breaker as I recall - take a ohm reading across the pigtail wire and the terminal the circuit power feed wire attaches to and see if you get a similarly high ohm reading on it on that breaker. Will be interested in your reply.

[Von Bickley]

I have been trying to avoid that since it appears that I do have a problem Von.

I'll sit back and watch.... Let us know what you find.

[Dennis McDonaugh]

Dennis I have been working on this with you (LOL) as I have been doing other things today. I am curious if you disconnected the power wire from the breaker and rechecked the circuit with the ohm meter if you would still get a ohm reading. Why I am thinking this is the breaker has a pigtail wire on it that goes to the buss bar on the neutral (or ground not sure on arc fault) which would electrically somehow tie them together inside the breaker I would think. I wonder if you are getting a reading from that and not a wiring issue. By disconnecting the power wire from the breaker you would eliminate the breaker from being a potentially high ohm electric conductor. If my thinking is right the breaker itself could be the source of the mega ohm reading you are seeing across the hot and ground wires. It likely shouldn't be a issue and has to do with how the arc fault is able to detect or operate.
I have worked on complicated wiring problems on computer controlled Allison transmissions and got weird ohm readings because of getting some continuity thru the circuit board in the ECU module when the harnesses were still connected to it. Regardless of anything being connected in the branch circuit you are working on, if the breaker is electrically connected to the power and ground internally it could give you a very high ohm reading. Even flipping the breaker off wouldn't prevent that I would assume as the electrical circuit would be on the load side of the breaker internally when flipping it off that connection I would think would still be there - just without power now.

You replaced the arc fault breaker as I recall - take a ohm reading across the pigtail wire and the terminal the circuit power feed wire attaches to and see if you get a similarly high ohm reading on it on that breaker. Will be interested in your reply.

I'll check it tomorrow Mike.

[Dennis McDonaugh]

I'll sit back and watch.... Let us know what you find.


Von, I'm not discounting your advice, I'm just wary of replacing the AFCI with a regular breaker and masking a real problem.

I've got six other AFCI breakers in the box and don't have any issues with those.

[Tom M King]

In thinking about pulling a new wire, are the boxes in the wall metal, or plastic? I've dealt with a bunch of each, and can offer advice on how to do it, if you need the information.

[Pat Barry]

Hey Dennis, how old is the wiring? I don't recall - I don't think this was new construction, right?

[ray hampton]

Dennis , I got a GFCI in one bathroom and it keep tripping yesterday BUT seems to be okay today , this is the second time [I think ] and I believe that it acts up when a outside outlet gets wet

[Duane Meadows]

Not knowing what type meter was used and under what conditions, 1 Megohm of resistance would allow about 100 micro amps of leakage current. That should be well below what the AFCI should trip at.

Since the AFCI sees arcs as RF(radio frequency), I still think that especially with as much wire as that circuit seems to have, a high power CB radio going down the street would possible cause the AFCI to trip. It would also explain the highly intermittant aspect of the situation. If that is the case, Many ham radio operators can probably help with filtering the circuit, although that would make the AFCI less sensitive, period!

Else you have either a loose connection, or something like a staple thru the wiring somewhere. I think I would try a milliamp meter in series with the circuit with all loads off but the AFCI powered up. Any fluctuation over time could indicate a problem. Would of course require either a lot of meter watching or a recording meter! Then disconnect outlets from the end of the circuit toward the AFCI till the problem goes away!

Measuring resistance on a dead circuit, IMHO, is quite unlikely to locate the problem. Unless you are seeing like 10-50 thousand ohms or less!

Also it seems from my research into your problem, that neutral to Safety Ground contact can trip the AFCI.

Just my 40 years as an electronic tech thinking out load so to speak!

[Brian Elfert]

Dennis , I got a GFCI in one bathroom and it keep tripping yesterday BUT seems to be okay today , this is the second time [I think ] and I believe that it acts up when a outside outlet gets wet

Older houses often shared one GFCI receptacle for the bathroom and the outside outlets. My parent 's house has one GFCI receptacle for the entire house. It was apparently cheaper to run wire than to buy GFCI receptacles back in 1979. Try putting one of the newer outlet covers on the outside outlet that keep water out better.

[Rich Engelhardt]

Dennis , I got a GFCI in one bathroom and it keep tripping yesterday BUT seems to be okay today , this is the second time [I think ] and I believe that it acts up when a outside outlet gets wetWe have a GFCI @ one of our rentals that we've replaced three times now in a little under two years.
We've use a Cooper, a Leviton and a Harbor Freight & they all three do the same thing.
The GFCI will function fine as long as it doesn't get tripped.
Once it get's tripped though, it's all over for it. It becomes "flakey" and unreliable.
Sometimes it goes days or weeks between tripping and sometimes it trips right away as soon as a load is plugged into it.

We replace it & it works fine, up until the point the tenant (or the tenant's aunt that comes over to watch her daughter) absent mindedly plugs her counter top oven into it.

From the reading and research I've done on GFCI outlets, that seems to be fairly common/normal.
Newer GFCI's I'm told, also have a lifespan of only a certain number of years before they get too sensitive.

BTW - I don't know if arc fault outlets are like that or not or if the QC is any better on them than it is on GFCI outlets - but - we can usually count on one bad outlet out of a couple of boxes of 6.
We buy six packs of GFCI outlets when they go on sale anywhere. Sometimes it's Cooper, sometimes Leviton and sometimes Harbor Freight.
It doesn't seem to matter what brand they are.

[Dennis McDonaugh]

Sorry for the delay, been working on other things. This is new construction, just about 11 months old and I called in a warranty repair. I have been reluctant to do this because we built the house and the electrical contractor just installed the breaker panels and wiring to the boxes, switches and outlets. Waiting for a reply, but I know there is going to be some finger pointing, but I am stuck as this is not as simple as I thought it would be.

[Dennis McDonaugh]

In thinking about pulling a new wire, are the boxes in the wall metal, or plastic? I've dealt with a bunch of each, and can offer advice on how to do it, if you need the information.

I'm thinking this is going to be the fix, but it's not going to be easy because there is a floor in the attic above the laundry room (location of the breaker) and hall. All the interior walls are also filled with insulation.

[Dennis McDonaugh]

Not knowing what type meter was used and under what conditions, 1 Megohm of resistance would allow about 100 micro amps of leakage current. That should be well below what the AFCI should trip at.

Since the AFCI sees arcs as RF(radio frequency), I still think that especially with as much wire as that circuit seems to have, a high power CB radio going down the street would possible cause the AFCI to trip. It would also explain the highly intermittant aspect of the situation. If that is the case, Many ham radio operators can probably help with filtering the circuit, although that would make the AFCI less sensitive, period!

Else you have either a loose connection, or something like a staple thru the wiring somewhere. I think I would try a milliamp meter in series with the circuit with all loads off but the AFCI powered up. Any fluctuation over time could indicate a problem. Would of course require either a lot of meter watching or a recording meter! Then disconnect outlets from the end of the circuit toward the AFCI till the problem goes away!

Measuring resistance on a dead circuit, IMHO, is quite unlikely to locate the problem. Unless you are seeing like 10-50 thousand ohms or less!

Also it seems from my research into your problem, that neutral to Safety Ground contact can trip the AFCI.

Just my 40 years as an electronic tech thinking out load so to speak!

I am getting such flaky readings--I seem to have some continuity between hot and ground at several different places, even with wiring disconnected, that I suspected the meter was wrong. I have about 100' of 12 gauge wire left over from the garage wiring and I ohmed that out just to be sure. The meter reads infinite between each wire and short form one end to the other so now I'm sure its functioning properly.

[Dennis McDonaugh]

I disconnected the hot and neutral at the breaker and took apart the pigtail in the bedroom light switch. That leaves me a wire, disconnected at either end, from the light box to the breaker box. I have some continuity between the ground and hot. I also have some continuity between the hot and ground going the other way. I can go down the line disconnecting switches, outlets and lights and confirm the continuity, the only thing that changes is the reading.

I have strange behavior when I reconnect everything.

The breaker blows immediately if I switch either the fan or light in the bedroom on. This was the original problem.
The hall lights, dining room lights, foyer lights, and kitchen lights all can trip the breaker, but not immediately. This is weird. I flipped the hall light on and it tripped the breaker. I reset the breaker and the hall light didn't trip the breaker the next time I turned it on, but the foyer light did. I reset the breaker, turned the foyer light on and it didn't trip the breaker so I tried the hall and kitchen and it didn't trip the breaker either so I tried the dining room light and it did trip the breaker. It just goes 'round and 'round in a seemingly random pattern. Reset the breaker and one of the light switches will cause it to trip, but there is no telling which one will do it at any time. Also, if I reset the breaker and do nothing it will trip after a random period of time.

I quit.

[Phil Thien]

I disconnected the hot and neutral at the breaker and took apart the pigtail in the bedroom light switch. That leaves me a wire, disconnected at either end, from the light box to the breaker box. I have some continuity between the ground and hot. I also have some continuity between the hot and ground going the other way. I can go down the line disconnecting switches, outlets and lights and confirm the continuity, the only thing that changes is the reading.


What kind of meter are you using?

[Pat Barry]

I disconnected the hot and neutral at the breaker and took apart the pigtail in the bedroom light switch. That leaves me a wire, disconnected at either end, from the light box to the breaker box. I have some continuity between the ground and hot. I also have some continuity between the hot and ground going the other way. I can go down the line disconnecting switches, outlets and lights and confirm the continuity, the only thing that changes is the reading.

I have strange behavior when I reconnect everything.

The breaker blows immediately if I switch either the fan or light in the bedroom on. This was the original problem.
The hall lights, dining room lights, foyer lights, and kitchen lights all can trip the breaker, but not immediately. This is weird. I flipped the hall light on and it tripped the breaker. I reset the breaker and the hall light didn't trip the breaker the next time I turned it on, but the foyer light did. I reset the breaker, turned the foyer light on and it didn't trip the breaker so I tried the hall and kitchen and it didn't trip the breaker either so I tried the dining room light and it did trip the breaker. It just goes 'round and 'round in a seemingly random pattern. Reset the breaker and one of the light switches will cause it to trip, but there is no telling which one will do it at any time. Also, if I reset the breaker and do nothing it will trip after a random period of time.

I quit.
I'll bet you a nickel that there is a wire pierced by a nail somewhere in the run. It probably was there from day 1 when the electrician installed the wiring and it finally caused a problem due to temperature change, and or breakdown. I think new wiring is the best fix unless you want to rip down the Sheetrock to confirm the failure. Given what you said about it being new construction I would insist on warranty replacement at no charge to you.

[Duane Meadows]

I agree with Pat, if it's new construction, let the contractor pull his hair out over it:D

[Dennis McDonaugh]

What kind of meter are you using?

It's a Fluke DVM.

[Tom Stenzel]

I remember decades ago when we had problems at work with communication cables we would use a time domain reflectometer to find where the problem was. I'd hate to think that you would need to those lengths to find a house wiring problem.

One time I got dragged into repairing a home intercom system in a newly constructed house. I don't think there was a cable anywhere that didn't have a staple sunk through it. A true nightmare to repair.

If the contractor is at fault he needs to be leaned on to make it right.

-Tom

[ray hampton]

I'm thinking this is going to be the fix, but it's not going to be easy because there is a floor in the attic above the laundry room (location of the breaker) and hall. All the interior walls are also filled with insulation.

is the insulation the matt type or pump-in type insulation ? your insulation could be forcing a wire to move in a hazard manner

[Phil Thien]

It's a Fluke DVM.

So if you have a leg from the load center to a box for a receptacle (for example), and with both ends detached you find continuity. And you also have a leg from that receptacle box to (for example) a box with a switch, and with both ends detached you also fine continuity. And if you have yet another leg (same as the other two) and you're finding continuity on THAT one, then I'd guess maybe you're using your fingers to hold the probes to the wires and the continuity is your body?

I can't imagine you're going to have multiple bad legs.

[John Lanciani]

So if you have a leg from the load center to a box for a receptacle (for example), and with both ends detached you find continuity. And you also have a leg from that receptacle box to (for example) a box with a switch, and with both ends detached you also fine continuity. And if you have yet another leg (same as the other two) and you're finding continuity on THAT one, then I'd guess maybe you're using your fingers to hold the probes to the wires and the continuity is your body?

I can't imagine you're going to have multiple bad legs.

+1. As someone who maintains and uses $100,000 or so of fairly sophisticated test equipment (electrical substation testing) I'm thinking that there is probably some user error creeping in here. I'd personally put everything back together, put a regular breaker in the panel, and measure current on the circuit with everything turned off (with the breaker on). Depending upon what model Fluke you're using you may already have what you need but you do need a fairly sensitive ammeter to test the circuit this way (a Fluke 289 for example will measure micro-amps) . If there is leakage it will be easily evident; if there is no leakage you've been chasing your tail.

[Dennis McDonaugh]

So if you have a leg from the load center to a box for a receptacle (for example), and with both ends detached you find continuity. And you also have a leg from that receptacle box to (for example) a box with a switch, and with both ends detached you also fine continuity. And if you have yet another leg (same as the other two) and you're finding continuity on THAT one, then I'd guess maybe you're using your fingers to hold the probes to the wires and the continuity is your body?

I can't imagine you're going to have multiple bad legs.

I have continuity both directions. I'm definitely sure I have an issue between the breaker box and the light switch box because there isn't anything there but the wire. It can't be more than 20' feet between the two. Then I have continuity somewhere down stream of the light switch box, but I don't know where. I know how to use a Ohmmeter. I was an electronics tech for 25 years in the Air Force and I'm using a high $$ Fluke meter with clip leads. I'm not an electrician however.

[Chuck Wintle]

+1. As someone who maintains and uses $100,000 or so of fairly sophisticated test equipment (electrical substation testing) I'm thinking that there is probably some user error creeping in here. I'd personally put everything back together, put a regular breaker in the panel, and measure current on the circuit with everything turned off (with the breaker on). Depending upon what model Fluke you're using you may already have what you need but you do need a fairly sensitive ammeter to test the circuit this way (a Fluke 289 for example will measure micro-amps) . If there is leakage it will be easily evident; if there is no leakage you've been chasing your tail.

I wonder if the OP ever had an electrician visit to see the problem. So many opinions and possible solutions but if the OP does not understand what is what then it cannot help. JMHO

[Dennis McDonaugh]

+1. As someone who maintains and uses $100,000 or so of fairly sophisticated test equipment (electrical substation testing) I'm thinking that there is probably some user error creeping in here. I'd personally put everything back together, put a regular breaker in the panel, and measure current on the circuit with everything turned off (with the breaker on). Depending upon what model Fluke you're using you may already have what you need but you do need a fairly sensitive ammeter to test the circuit this way (a Fluke 289 for example will measure micro-amps) . If there is leakage it will be easily evident; if there is no leakage you've been chasing your tail.

I'm done with it, whether its self-inflicted or not, I'm chasing my tail and will let the electrical contractor handle it.

[ray hampton]

I'm done with it, whether its self-inflicted or not, I'm chasing my tail and will let the electrical contractor handle it.



after your contractor solve the electrical problem will you tell us what the problem is/was

[Dennis McDonaugh]

after your contractor solve the electrical problem will you tell us what the problem is/was

Of course I will. Too many people have offered advice not to provide closure!

[Chris Padilla]

Of course I will. Too many people have offered advice not to provide closure!

Plus curiosity is just KILLING us as to the culprit here!

[Jim Koepke]

Then I have continuity somewhere down stream of the light switch box, but I don't know where.

My first guess would be a bulb in a light socket.

How many ohms your meter is reading tells the story. If it is in the 10-30 ohm range it may be a light. A bathroom fan motor may be higher. A high resistance could be pierced insulation. It may not be a problem until a little heat expands the wires and the resistance drops enough to open the breaker.

This could be something caused by an inexperienced sheet rocker.

jtk

[Dennis McDonaugh]

I had an electrician visit yesterday and he spent the first hour and a half doing all the things I had done and seeing all the things I had seen. He disconnected several light switches and outlets in an effort to isolate the problem to one area pretty much without any luck. After he saw that turning on nearly any light switch could trip the breaker, but didn't necessarily trip the breaker every time the switch was turned on, he did something I didn't do and never even thought about doing. He disconnected the fan and light in the bedroom, including the neutral and ground wires. I had only disconnected the hot lead. After that everything worked! Well, except the fan and light. After he left, I ohmed out the fan and the neutral and ground are shorted together somewhere inside the fan or lamp. I'm not sure I actually understand the relationship between ground and neutral in a circuit. Aren't they connected in the breaker box?

I'm still mystified about the continuity I read between the hot and ground on the circuit. I showed the electrician what I was reading on my meter and he measured it with his. He didn't have a multimeter per se, but an electrical circuit tester. While mine showed a very high impedance connection between the two, his meter kept trying to display a number, but would never settle on any digits. He said that was an open as far as he was concerned.

Anyway, it works and we bought another fan to replace the bad one.

Thanks to everyone who provided advice.

[Mike Lassiter]

Great - glad it wasn't something that required tearing into the wiring inside the walls or ceiling. Thanks for the follow up.

Also glad you didn't just change out the breaker as several advised. There was a problem as you and some of "us" suspected. Don't know if it could have caused a fire had you done that and stopped digging into this, but now you have peace of mind knowing the real problem is fixed.

[ray hampton]

Anyway, it works and we bought another fan to replace the bad one.

Thanks to everyone who provided advice.

I am glad that you got the problem solved

[Tom M King]

Glad to hear what it was, and that it wasn't in the wall. When testing with a digital voltmeter, just throw out any oddball small readings. Neutral and Ground, or Grounding and Grounded wires, are indeed "connected" to ground in the service panel, but an arc fault breaker will trip if touching anywhere else in the circuitry. I guess the current has a problem figuring out which way to go, so the AFCI says it's not good.

[Chuck Wintle]

I had an electrician visit yesterday and he spent the first hour and a half doing all the things I had done and seeing all the things I had seen. He disconnected several light switches and outlets in an effort to isolate the problem to one area pretty much without any luck. After he saw that turning on nearly any light switch could trip the breaker, but didn't necessarily trip the breaker every time the switch was turned on, he did something I didn't do and never even thought about doing. He disconnected the fan and light in the bedroom, including the neutral and ground wires. I had only disconnected the hot lead. After that everything worked! Well, except the fan and light. After he left, I ohmed out the fan and the neutral and ground are shorted together somewhere inside the fan or lamp. I'm not sure I actually understand the relationship between ground and neutral in a circuit. Aren't they connected in the breaker box?

I'm still mystified about the continuity I read between the hot and ground on the circuit. I showed the electrician what I was reading on my meter and he measured it with his. He didn't have a multimeter per se, but an electrical circuit tester. While mine showed a very high impedance connection between the two, his meter kept trying to display a number, but would never settle on any digits. He said that was an open as far as he was concerned.

Anyway, it works and we bought another fan to replace the bad one.

Thanks to everyone who provided advice.

Sometimes the pros really know all the tricks!

[Andrew Pitonyak]

I'm still mystified about the continuity I read between the hot and ground on the circuit. I showed the electrician what I was reading on my meter and he measured it with his. He didn't have a multimeter per se, but an electrical circuit tester. While mine showed a very high impedance connection between the two, his meter kept trying to display a number, but would never settle on any digits. He said that was an open as far as he was concerned.

If I connect a load such as a light bulb then the light bulb serves as a connection between hot and neutral. There is some resistance across the bulb. Neutral and ground are tied together at the breaker box.

[Phil Thien]

I had an electrician visit yesterday and he spent the first hour and a half doing all the things I had done and seeing all the things I had seen. He disconnected several light switches and outlets in an effort to isolate the problem to one area pretty much without any luck. After he saw that turning on nearly any light switch could trip the breaker, but didn't necessarily trip the breaker every time the switch was turned on, he did something I didn't do and never even thought about doing. He disconnected the fan and light in the bedroom, including the neutral and ground wires. I had only disconnected the hot lead. After that everything worked! Well, except the fan and light. After he left, I ohmed out the fan and the neutral and ground are shorted together somewhere inside the fan or lamp. I'm not sure I actually understand the relationship between ground and neutral in a circuit. Aren't they connected in the breaker box?

I'm still mystified about the continuity I read between the hot and ground on the circuit. I showed the electrician what I was reading on my meter and he measured it with his. He didn't have a multimeter per se, but an electrical circuit tester. While mine showed a very high impedance connection between the two, his meter kept trying to display a number, but would never settle on any digits. He said that was an open as far as he was concerned.

Anyway, it works and we bought another fan to replace the bad one.

Thanks to everyone who provided advice.

Wow, in light of this new information I'd say post #19 in this thread was prophetic, somebody give that guy a cigar!

How could he have possibly known that? That guy is a genius.

But I've also heard he is pretty immature.

[Chris Padilla]

Wow, in light of this new information I'd say post #19 in this thread was prophetic, somebody give that guy a cigar!

How could he have possibly known that? That guy is a genius.

But I've also heard he is pretty immature.

...and quite arrogant at times.... :p

[Dennis McDonaugh]

Wow, in light of this new information I'd say post #19 in this thread was prophetic, somebody give that guy a cigar!

How could he have possibly known that? That guy is a genius.

But I've also heard he is pretty immature.

Indubitably, LOL

[Jeff Bouley]

Hi Dennis, bare with me, this is the first time I reply to anything on forums. The more often a breaker trips the less accurate it can become. It's possible that the breaker is now compromised, but that doesn't nessessarily explain why the breaker tripped in the first place. If I read your thread correctly, you mentioned that the circuit in question is connected to a gfci breaker. these breakers are usually used for wet locations ie: bathrooms, kithens, pool filters etc. If there aren't any of these types of loads on the circuit, it's not nessessary to have it on that circuit (Double check with your town electrical inspector, he/she has the last word on these matters). The first thing you could try is to identify all loads connected to that circuit. Once you know what is on the circuit you can disconnect the hot wire from the breaker and use a multi meter set to ohms and test the hotwire to earth ground to see if there is a short circuit (the meter will go from zero ohms to full scale deflection). If that's the case, now you can remove the loads one at a time until the short circuit opens on the meter. Once you know which load is causing the short, reconnect all other loads that was previously disconnected and reconnect the circuit to the breaker and reactivate the breaker. Unless the circuit is over loaded, the circuit should no longer trip. Depending on the type of breaker box and breakers you have, some of these can be a bit pricey to replace on a hunch. Hope this helps, Jeff Bouley

[ray hampton]

Indubitably, LOL

Dennis, your last post was July 10 th, time to report in and keep the forum well-inform

[Jason White]

Sorry, I'm late to the party. Sounds like you've got an "arc fault circuit interrupter" and not a "ground fault circuit interrupter." GFCI's are for wet areas. AFCI's are for bedrooms and such. If you don't see any evidence of arcing in any of the electrical boxes (both switches and fixtures), then the breaker is likely toast. I'd try replacing the breaker and see what happens. If the issue persists, get a real electrician in there.


Sorry for the long story, but this has been going on a few days.

The circuit breaker for our second bedroom tripped a few days ago. It's used as an office and at the time the overhead light and ceiling fan were on as well as an LED TV and a cable box. I reset the breaker and it immediately tripped again so I turned the light and fan off and unplugged everything in the room, including those devices that weren't on at the time the breaker tripped. The breaker didn't immediately trip, but as soon as I turned on the overhead light it tripped. That was an "Aha" moment and I thought I'd discovered the issue. Just to make sure I turned the light off, reset the breaker and turned the light on and...nothing. Then, I turned on the ceiling fan and it tripped the breaker again. At that point I pulled the ceiling fan and light fixture down, checked the wiring and reinstalled them. I turned everything on and the breaker didn't trip...until a couple hours later.

This time I disconnected the black leads from the two switches that control the ceiling fan and light. Then I reset the breaker and it didn't trip so I just figured I had some kind of internal wiring problem in the fan or switches and decided to pick up a fan and two light switches from the big box store on the way home from work the next day. I reconnected the switches, plugged everything back in and told Kathy not to turn the overhead light or fan on. About noon I got a call from Kathy and she says the entry foyer light is "burned out" and we don't have any extra bulbs, can I pick up one from the store when I get the fan. I tell her sure and think nothing more of it. A couple hours later she calls and tells me the hall light is also out and the circuit breaker in the second bedroom tripped again because nothing electrical in the room works. I decided to skip buying the fan and investigate some more.

The circuit labeled Bedroom 2 in the breaker box powers the outlets in the bedroom, the overhead fan and light in the bedroom as well as the hall light, the light in the foyer and a light over the breakfast area in the kitchen. All lights except the kitchen light use low wattage CFLs. The kitchen uses a 60 watt incandescent bulb.

Armed with this knowledge I disconnected the overhead light and fan switches in the bedroom again. That left the switchs, light and fan unpowered. Then I turned on the hall, foyer and kitchen lights and they ran all night and half the next day until the breaker tripped. I had Kathy reset the breaker and turn off the kitchen and foyer light. The hall light ran for a couple days and then tripped the breaker. I turned off the hall light and turned on the foyer light and its still running.

At this point I'm thinking the breaker may be the issue. One other piece of information--the breaker is a GFI breaker, but as near as I can tell, none of the outlets it powers are outside or in a wet area. I checked the outlets in the laundry and bathroom and this breaker definitely doesn't power any of them or the outlets near the front and back door.

[Dennis McDonaugh]

Fixed. See post 91.